1. Field of the invention
The present invention relates to a motion control system for a vehicle and more particularly to a motion control system capable of avoiding a contact with an obstacle by turning around the obstacle.
2. Prior art
In recent years, in order to avoid collisions with obstacles ahead of a vehicle, an automatic brake control system has been developed in which the distance between the vehicle and an obstacle is detected based on images taken by a stereoscopic camera or a laser-beam radar, and when the distance is smaller than a predetermined value, the brake is applied automatically.
For example, Japanese Patent Application Laid-open No. Toku-Kai-Hei 7-149193 discloses a technique in which when the distance between detected by an inter-vehicle distance detecting apparatus is smaller than a calculated safe distance, an automatic brake is operated. In this technique, the safe distance is calculated taking a maximum deceleration which the vehicle can generate according to the condition of tires of respective wheels, road gradients and the like into consideration.
The technique for preventing collisions with obstacles is largely dependant upon how to calculate a deceleration of the vehicle. Since there are many factors affecting the deceleration of the vehicle, it is difficult to take all of these factors into consideration and therefore there is no assurance that the vehicle can stop before an obstacle. Further, an extreme deceleration is not preferable.
It is an object of the present invention to provide a motion control system capable of surely avoiding contact with an obstacle located at the front of a vehicle by turning.
In order to attain the object, a motion control system including an obstacle recognition means for detecting an obstacle in front of the vehicle and for obtaining an information of the obstacle and a running condition detecting means for detecting running conditions of the vehicle, comprises a braking distance judging means for when a deceleration is applied to the vehicle judging whether or not the vehicle can finish the deceleration without contacting the obstacle based on the information of the obstacle and the running conditions, a first parameter calculating means for calculating a first parameter necessary to take a lateral avoidance motion based on the obstacle information and the running conditions, a second parameter calculating means for calculating a second parameter representing a parameter presently generating in the vehicle based on the running conditions, a target parameter establishing means for when it is judged that the vehicle can not finish the deceleration without contacting the obstacle, establishing a target parameter by comparing the first parameter with the second parameter and a vehicle behavior control means for generating the lateral avoidance motion of the vehicle at least in accordance with the target parameter.